v3.26.1
Liability for Unpaid Losses and Loss Adjustment Expenses (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]        
Unpaid losses and LAE at beginning of period $ 1,802.5 $ 1,792.6 $ 1,805.8 $ 1,808.2
Less reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE 383.1 407.1 386.5 412.4
Net unpaid losses and LAE at beginning of period 1,419.4 1,385.5 1,419.3 1,395.8
Losses and LAE, net of reinsurance, incurred during the period related to:        
Current period 124.1 141.5 254.6 262.5
Prior periods (0.3) 0.3 (0.4) 1.6
Total net losses and LAE incurred during the period 123.8 141.8 254.2 264.1
Deduct payments for losses and LAE, net of reinsurance, related to:        
Current period 24.2 26.0 30.6 34.0
Prior periods 123.9 115.5 247.8 240.1
Total net paid losses and LAE during the period 148.1 141.5 278.4 274.1
Ending unpaid losses and LAE, net of reinsurance 1,395.1 1,385.8 1,395.1 1,385.8
Reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE 380.1 401.0 380.1 401.0
Unpaid losses and LAE at end of period 1,775.2 1,786.8 1,775.2 1,786.8
Impact of the LPT Agreement 1.5 1.7 2.7 3.3
Involuntary Assigned Risk Business [Member]        
Losses and LAE, net of reinsurance, incurred during the period related to:        
Prior periods $ (0.3) $ 0.3 $ (0.4) 0.9
Voluntary Risk Business [Member]        
Losses and LAE, net of reinsurance, incurred during the period related to:        
Prior periods       $ 0.7